


Power's Out

by Madness_of_Xara



Category: Undertale (Video Game)
Genre: Couch Sex, F/M, Fluff, PWP, Sex, Smut, Tentacles
Language: English
Status: Completed
Published: 2017-10-11
Updated: 2017-10-11
Packaged: 2019-01-16 04:02:47
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 4,817
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/12335088
Author URL: https://archiveofourown.org/users/Madness_of_Xara/pseuds/Madness_of_Xara
Summary: A commission I wrote for StrawberryHoney-Skeleton-Mommy!





	Power's Out

**Author's Note:**

  * For [StrawberryHoney-Skeleton-Mommy](https://archiveofourown.org/gifts?recipient=StrawberryHoney-Skeleton-Mommy).



It had been ten years since the fall of the barrier that had trapped Monsters under Mount Ebott. Since then, Monsters had been slowly moving to the Surface bit by bit, getting jobs and buying houses and just overall making lives for themselves up there. Some Monsters still lived in the Underground, but that was simply because they figured that they were too old to leave or just because they were already quite nicely settled in their homes. That was well and fine, and really, that just meant that they didn’t have to worry too terribly about having to fight for equality, something that had been growing steadily better and better over the years.

Mettaton had made it as a celebrity up on the Surface, working it as a supermodel, both for male clothing and female clothing, fashion designer, and actor. He was never really too picky about the roles he played as long as he got at _least_ five minutes of camera time. Eventually, he had piloted two shows of his own and was even staring in three movies and two television programs separate from his own. Napstablook was his music choreographer and orchestrator, having him do the audio and music for his programs. The two of them lived together in a lavish house by the beach.

Undyne was working as a gym instructor at the local gym, helping people work out and get stronger by making sure they did their routine, drank their protein shakes, and stretched properly before actually doing anything that would hurt their muscles otherwise. She lived with Alphys, her wife now of three years, having been the one to propose one fateful night after coming home bloodied and bruised and cut up from an attempted mugging where someone tried to steal the very expensive ring she had bought the Lizard Monster. Undyne had proposed the moment she walked through the door that night, despite how Alphys was freaking the fuck out and trying to get her some medical attention. It was both totally _not_ romantic and completely and utterly _fucking adorable_.

Alphys worked from home, going to human college part time for a degree in the medical field. She wanted to be of help in whatever ways she could, and really, she had made some pretty amazing breakthroughs in the Underground. She was researching diseases and their genetic sequences, working on possible cures for the ones that were only in the treatable stages and the ones that were completely incurable thus far. She was close to breaking the code on certain types of cancer, though as it were, she was only able to make it better treated rather than _cured_. It was a step in the right direction, though. Thanks to Mettaton, she and Undyne were able to live comfortable lives in a nice little house of their own just outside of the city. He always made sure that if they needed it, they would have a cab to come by to pick them up and take them wherever they needed to go.

Muffet worked with Grillby in a nice little diner bar, the Spider Monster working the day shift serving spider baked goods and drinks, such as cider and milk, while the Flame Monster worked the night shift, serving alcohol and burgers and fried foods. It wasn’t much at first, but they had grown to be quite the powerful duo, and in their growth came the growth of the diner bar which had been named Grillby and Muffet’s Smokin’ Spider. It was a weird name to some, but others thought it was kind of funny and cutesy.

King Asgore was a gardener at the first Monster and human integrated school where his wife – yes, they had gotten back together after about four or five years – worked. Queen Toriel was living her dream of being a school teacher for children, both human and Monster alike. She had won two teacher of the year awards in a row, and currently, she was working on her third, though she wasn’t sure if she would be able to win it this time since she was expecting a child. It had taken a while for her and Asgore to even consider having another child after what happened to Asriel, but they had finally decided that it would be best if one, they had a living heir (Frisk didn’t count since they were the Human Ambassador – they already had way too much on their plate to handle as it was without the possibility of becoming the next Queen to add in on top of it), and two, they were happy. It was what Asriel would have wanted, they knew.

They still had no idea about Flowey’s true identity, though they treated him kindly and loved him all the same.

Flowey, after about three years of staying in the Underground, was brought up to the Surface by Frisk. Originally, the flower was not amused, having told Frisk that he was fine staying in the Underground, that he wanted to be alone. But after some time, Flowey realized that he had missed his enemy turned friend, and actually would demand to be brought everywhere by the child. Currently, he rested in a pot on the kitchen counter in Frisk and the Skeleton brothers’ house, watching cooking shows when nobody was around and baking cakes and pies like his parents did, though he would _never_ admit to it, claiming that Toriel or Asgore stopped by and dropped the baked goods off.

Frisk knew the truth, of course, but they would just smile and play along with the blatant lie, making the comment that it was really nice of them. They would make sure to compliment the food out loud as much as possible so Flowey would know that he did a good job.

Papyrus worked as an aspiring chef at a local restaurant, being taught the ropes and how to cook a multitude of dishes. He had improved nicely, and he was sure that he was going to be receiving a promotion and raise soon. He would be right of course, but he didn’t know that yet. He just had a feeling, and that was all he had to go on, really. He worked full time, and more often than not, he worked overtime, but it didn’t really bother him. It was like he was a huge bundle of energy that couldn’t be stopped or deterred by anyone or anything!

Then there was Sans and Frisk. Sans didn’t really work a job, per se. He ran his own hot dog stand just outside of their house, and sure, it brought in a good amount of money, but he didn’t call it a job. He did it because it gave him something to do while Frisk was at college for law with Flowey in tow. They didn’t live too far from the campus, so Frisk would walk there every day they had a class to go to. The two of them had been going out for two years now, the pair having started to date when Frisk came to be eighteen years old, and they were going strong. Frisk’s classmates tried to convince them that they would get sick of San’s jokes and puns before long, but it didn’t seem to be that way. To them, no matter what, Sans was as funny now as he was the day they met ten years prior, if not funnier.

It had been a productive ten years, that was for sure.

It was just seemingly another day for Frisk, cooking a nice little dinner while Flowey stared out the window. It was pouring down rain for what seemed like forever now. Last Frisk had seen, Sans was out in the living room sleeping on the couch, having not opened the hot dog cart that morning due to the weather. Papyrus was at work, he had been since early that morning, and he wouldn’t be home for a few hours, leaving the three of them home alone with one another until he came back.

“The weather looks like it’s getting worse,” Flowey commented offhandedly after a while. Frisk glanced out the window, their blue eyes taking in the heavy downpour outside. The sight brought a frown to their soft, plump lips.

“Yeah, it sure looks that way,” they agreed in their soft voice. “I hope it dies down before Papyrus heads home from work.” They turned back to their cooking, making the comment to themselves mentally that the weather was the _tiniest_ bit off about the forecast that day. And by ‘the tiniest bit,’ they meant they were completely off. The weather forecast had said that it was supposed to be clear skies that day. Obviously, they were wrong.

After a few minutes, they finished cooking, taking the skillet off of the burner and setting it to the side, loading up four plates with the food they made. They wrapped one plate of food in saran wrap before placing it in the microwave. They weren’t sure if Papyrus would be hungry once he got home, but it was always nice to have something made just in case he was. They then took another plate and sat it beside Flowey. He constantly said that he never needed to eat anything, but they knew that he liked their cooking, always cleaning the plate of food whenever he was left alone before washing it to try and hide the evidence that he ate it. The few times Frisk caught him in the act, he would get flustered and scoff, lying to them by saying that he tossed it out the window or into the trash. It was blatantly obvious that he was lying, but Frisk didn’t have the heart to call him out on it. They smiled a little to themselves as they grabbed the last two plates and made their way to the living room.

Sans was still asleep on the couch, his hands in his pockets and head leaning against his shoulder, his body upright and eye sockets ‘closed.’ He looked so peaceful when he slept. At least, he did whenever his sleep wasn’t being plagued with nightmares. Over the course of the last few years, the human had learned about the nightmares, and honestly, they were saddened that Sans even had them in the first place. They only learned what those nightmares contained, though, recently and they finally understood why Sans had never brought them up before. It had taken an accident in which Sans had attacked them after they woke up from a nightmare in the privacy of their bedroom for them to learn the truth.

Sans still felt bad about that.

Frisk set the plate they made for him on the coffee table in front of them, then started to shake him awake. “Sans. Sans, wake up,” they said softly. They watched as he slowly stirred awake, his eye lights flickering into existence slowly. When those lights, groggy yet steady, landed on Frisk, his smile seemed to widen ever so slightly.

“Hey, kid… How long was I out?” he asked softly, slowly sitting up and stretching out his limbs.

“Long enough for me to cook dinner,” Frisk admitted with a small shrug. “Did you sleep well?”

Sans hummed, leaning forward and grabbing the plate his girlfriend had made for him, holding it in his lap and taking in its lovely aroma. Frisk was a natural in the kitchen, that was for certain. Probably helped that they took a lot of cooking classes after high school growing up. He took the fork he was given and started to eat, humming happily. “Delicious, as always.”

“Thanks,” Frisk giggled softly. They leaned against the Skeleton as they started to eat too. Once they were done, they set the plates aside and cuddled. “Any idea how long it’s supposed to rain?”

“It’s raining?” Sans asked. He glanced out the window and his smile wavered a little. “Well, then… By the looks of it, it’s going to rain for a while.” He ran his hand across the top of his skull. “It should die down before Paps gets off work, though.”

“I hope so,” the human murmured, burying themselves deeper against the male’s jacket. “I know he hates driving in the rain. The water gets in his eye sockets and makes him really uncomfortable…”

Sans wrapped his arm around Frisk tight and pulled them in closer. He rubbed their shoulder affectionately. “Heh. I remember last time, he kept complaining that he could still feel it even though it had been a week later and we had cleaned his eye sockets with a hand towel.”

Frisk giggled softly. “I remember that, too. It was really funny.” She sighed then, closing her eyes. “Still, though. The weather forecast was off again, so knowing him, he left the top down…”

The Skeleton hummed his silent agreement before glancing down at Frisk. The two of them had been dating for a while. Two years now, as it were. And in those two years? They had grown closer than ever before. No other timeline could ever hope to match, and admittedly, Sans was glad to be experiencing this one true timeline that they were in together. It was his favorite out of all of the ones he had gone through.

They cuddled for a while, just simply watching the television without really paying much attention to it until-.

 _BOOM_!!

There was a huge clap of thunder outside followed by a blinding brightness of a lightning bolt, cutting out the power all at once. The only light that was in the room then were Sans’s eye lights, flickering blue and orange in alarm before calming to their gentle white. Frisk had jumped, burying themselves deeper into Sans’s side. They hated thunderstorms, especially when they seemed to be right over their heads like the one outside seemed to be. Sans held them close, as though to silently inform them that he was there and he wouldn’t allow anything to happen to them for as long as he was there. They relaxed, but they still seemed to be spooked ever the tiniest bit from the sudden loss of power.

Sans had to think of something to help them get out of their own head for a moment.

“You have unlimited data on your phone, yeah? Why not open up an app and watch some videos? I know you’ve been behind lately thanks to college…”

Frisk perked up a little at that. “Yeah, I am, huh?” They shifted a little, which in turn make Sans shift into a more comfortable position to accompany the both of them. They then pulled open a video and started to watch it. While they knew that it was only a distraction, it was proving to be a useful tactic. Sans smiled a little at that. That was good to know, that his plan had worked. He held them, arms around their middle. They usually didn’t cuddle like this unless… well, unless they had had sex right before. Not that they didn’t normally cuddle, they did, but certain positions were usually reserved for post sex sessions. It was an unspoken rule between the two of them, even if it wasn’t exactly an official rule between the two of them.

Speaking of, the two of them hadn’t had sex in over three months. When they had first gotten together, they had… explored one another, in more ways than one. It was strange, their first time, but once they had figured everything out, they had been together in a world of bliss. Frisk admittedly panicked after their first time, though, due to not knowing if Sans could get them pregnant or not and, foolishly, they had not really thought to wear protection. Thankfully, Frisk didn’t get pregnant, but since then, they had used protection every single time. Once they were married, they agreed, they would have sex without protection, to try and see if a human and Monster hybrid child _was_ possible. If not, they would always adopt. They planned to adopt either way, but still.

In those three months of no sex, however, they hadn’t really had the chance to do much other than some hurried oral or heated touching before bed. Actual sex was almost impossible for the two of them do with Papyrus in the house, plus the fact that the two of them were almost rarely ever home together at the same time whenever he was out. Whenever they had been alone, those times, though, they were too tired to do anything outside of nap with each other. This time, though…

Papyrus wouldn’t be home for a few hours.

And neither of them were tired.

Sans smirked ever so slightly, glancing down at Frisk. This was their chance to finally have sex again, given if they were willing. He tested the waters, rubbing their stomach soothingly before slipping his phalanges up their sweater. They shivered, but they didn’t stop him. He rested his hand on their smooth stomach just underneath their top, letting them get used to his hand being there before slowly trailing his hand up. His fingertips twitched when he was just underneath their breast, clad in a thin bra. He heard their breath hitch in their throat, though still, they said nothing. It was like they were waiting with bated breath, wanting to know what Sans had in mind, wanting to know what he would do next.

He slipped his hand that little bit higher and underneath the fabric of the bra to cup their breast, giving it a nice firm squeeze before kneading it ever so slightly, rolling it and squeezing it in his hand. He made sure that their nipple was caught between his phalanges, being forced to be rolled and pinched and pulled ever so slightly with every move he made. He listened as they started to whine ever so softly, breathing just the tiniest bit harder. It was amusing, listening to them make such noises. It was more than obvious that they were feeling just as pent up as Sans had been.

His hand peeled away from their breast, a soft, needy whine escaping from between their lips at the loss of contact. He trailed his bony fingers down along their lightly chubby stomach, tickling them ever so slightly. They squirmed and giggled, but they did not tell Sans to stop. No, why would they? They liked it, to be tickled breathless until he got back to the task at hand. He nuzzled his face against their neck, kissing the tender flesh there and nipping at it as he tickled them ever so slightly. He breathed a heavy sigh before slipping his hand further down, going into her pants. He rubbed them through their panties.

“You like this, don’t you, Frisk? The idea of getting fucked into the couch just makes you all wet and horny, doesn’t it?” They whined, words obviously failing them as they rolled their hips, trying to get more friction from his fingers. “Good.” He leaned in nice and close so he was practically breathing into their ear. “Because I plan on fucking you until you can’t move.” A low moan escaped their throat at that, one Sans groaned in response to. He could feel his magic swirling at the pit of his pelvis, slowly solidifying until it took a nice, firm form inside of his shorts. He sighed heavily. “Mm, I wonder what my cock looks like this time. Is it a normal ‘human’ cock, a typical monster cock, or something different this time?” Frisk tried to turn in his hold and he smirked, holding them firmly in place. “Ah, ah… Not yet.” They whined, to which he responded with a low, husky chuckle. “Patience, kid. _Patience_.” His voice was low and husky.

Frisk could feel their panties become simply drenched, that was how wet they were. They were trembling from need, from desire, but they knew this game. They had played it more than once. They both loved to play it and hated to play it. They loved it because the orgasm was definitely worth it. They hated it because it took so long to get to that point.

“P-please… S-Sans…” they whispered. When he seemed to ignore their pleas, they tilted their head and whined, thrusting against his fingers. They gasped softly and bucked their hips when he pulled their panties to the side, his slightly chilled phalanges almost like ice between their burning pussy lips. They were shuddering and whining louder than before, thrusting harder and trying to get his fingers inside of them. “F-fuck, please… Please, Sans, please…!”

“Please, what?”

“F-fuck me!” whined Frisk desperately.

“Your wish is my command,” chuckled Sans in a husky tone. He slipped two digits inside of them, thrusting them mercilessly and curling and twisting them around. Frisk was moaning like a common whore, something Sans absolutely _loved_. Especially since he rarely got to hear them moan at all. There were a flurry of curses escaping their lips. Frisk couldn’t help it. They had been pent up for too long, they _needed_ this. When his fingers deftly found their g-spot, they were on the verge of tears, moaning louder and without any shame, as if there was any in the first place. Just as they were getting close, so very, very close to the blissful edge, Sans stopped.

“N-no,” whined Frisk, attempting to rock their hips. They were held firmly in place.

“Ah, ah… You want a right, proper fuck, don’t you?” purred the male lowly as he pulled his hand from their panties. Oh, they had been dripping wet, alright. He formed a tongue inside of his mouth and opened it, lapping at his fingers hungrily. “Fuck, toots… You’re even more delicious than usual. I can’t wait to taste you more after I fuck you senseless.” He cleaned up his fingers before beginning to strip of his jacket and shirt, lazily kicking off his slippers, not caring where they landed to be quite honest, as long as they weren’t in the way. He was left only in his shorts, and there was a very obvious tent right at the base of his pelvis, glowing just the tiniest bit through the fabric.

Frisk saw him strip and immediately joined him, peeling off their sweater and jeans, leaving them in just their purple panties, which seemed to be darker from their arousal, and their pink sports bra. They straddled Sans’s waist, grinding against him, their clothing the only thing keeping them apart. They were no longer so close to climax, and that made them even more desperate to get off in whatever they could. “F-fully nude, o-or…?”

Sans pulled them down slightly, kissing them roughly. He reached down between them and pulled his shorts down just enough to let loose a writhing, glowing blue tentacle, one that would fill up the human in his lap nicely. He then pulled their panties aside and allowed the tentacle a moment to find its way to their pussy. Once it found it, it began to thrust between their pussy lips, rubbing their clit and labia in the most torturous of ways. Soft whimpers escaped from Frisk against Sans’s teeth, and once the tentacle found their entrance, they gasped softly and pulled away.

“O-oh!” Frisk moaned out breathily. “A-a tentacle this time… I-I don’t remember the last time we did that form…”

“Mm… I think we did shark last time,” chuckled Sans, rubbing their hips. “Let me know if you want me to stop.” With those words, the tentacle slipped deep inside of Frisk, stretching out their walls. It writhed deep inside of them, exploring and going as deep as it possibly could. Once it was completely buried, it wasted no time in thrusting itself in and out of them roughly drawing loud, shaky moans from the human. “F-fuck… G-guess I don’t really need to do any of the hard work, huh?” the skeleton groaned out.

Frisk kissed him roughly in response, taking one of his hands and placing it firmly over their breast.

Sans got the hint and slipped his hand underneath their bra, returning to his earlier methods of pleasing them. He didn’t notice more tentacles manifesting around the one inside of Frisk, not until he felt them wrap around their thighs firmly. He cursed softly. “Sh-shit… sorry, I-I’m having a hard time c-concentrating on my magic…”

“I-it’s okay. I-I like it,” moaned Frisk. The tentacles shivered in response, tightening just the tiniest bit. One tentacle slipped around behind them, rubbing their ass before spanking it roughly. The human squeaked in surprise. They moaned louder than before as another tentacle pushed its way inside of their pussy. “O-oh, god… F-fuck, I feel so full, Sans…” They started to bounce some on his lap. “I-I love it when you fill my pussy up like this.”

“W-well, y-you _did_ tell me that you could handle whatever I threw atcha,” Sans breathed out. He thrusted his hips up in time with their bouncing. “G-god, I remember being so scared when you asked me to double stuff you with the shark cocks… But your pussy just took it all, every inch…” He groaned a little louder, thrusting his hips a little faster and harder. “F-fuck!” He took their hips in his hands and reversed their positions, laying them on their back along the couch, panting hard as he started to thrust his hips frantically. “Y-you’re my dirty little whore, aren’tcha, Frisk? My dirty little human whore…! F-fuck! Y-you’re clenching my cock so hard…! Y-you know what you _do_ to me? I-I can’t go a day without thinking about you, about how you moan for me, about how beautiful you _fucking look_ …! _FUCK_!” He couldn’t keep his thoughts straight anymore. All he could see was Frisk, the way they looked so flushed and beautiful and just oh so wonderfully _fucked_.

“S-Sans,” moaned the human, moving their hands to place on his shoulders. Before they could quite reach, two tentacles lashed out and grabbed their wrists tightly, wrapping around them and pinning them down against the couch. The tentacle that had spanked them earlier wrapped around their middle, pulling their body against Sans with every thrust. The tip of that tentacle slithered down their body and rubbed at their swollen clit hungrily. They were moaning so loud it was a wonder their neighbors had yet to call and tell them to shut up. Then again, they were most likely at work themselves, having managed to get out before the storm outside started. “S-Sans! P-please, I’m so close…!”

Sans growled lowly, digging the tips of his phalanges into their hips. “J-just a little longer, toots. Th-then we can-!” His breath caught itself and he froze, buried deep inside of their pussy, stream after stream of hot cum pulsing through his cock. It poured deep inside of them, filling them to the brim. Once he was done, he collapsed some against them, panting hard. “F-fuck…” he breathed. The tentacles faded away, and he knew that Frisk was still close. He reached down between them and pushed his fingers deep inside of them, finding their g-spot immediately and rubbing it hard. It wasn’t long until Frisk was moaning his name and cumming hard around his fingers. Once they were sated, he pulled his fingers out and laid on top of his human. He was still trying to catch his breath.

Frisk, after having recovered some, kissed the top of his skull, panting softly. “We needed that,” they whispered softly, their voice mildly hoarse. Sans only could hum. The human smiled ever so slightly. “I love you, Sans… You know that, yeah?”

“’F course…” he murmured softly. He looked up at them, his left eye socket flashing a beautiful blue. “I love you, too… _You_ know that, right?”

The human giggled softly and hugged him tight. “Yeah… Yeah, I do.” Just then, the power returned to the house, exposing them for the after-sex mess that they had turned into.

“POWER IS ON!” Flowey yelled from the kitchen. “ALSO, I LIVE HERE, TOO! YOU REMEMBER THAT?! COURSE NOT! CAUSE YOU TWO HAD YOUR _FUN_ WITHOUT CONSIDERING-!”

“SORRY!” Frisk yelled back hurriedly, blushing heavily in embarrassment. Sans was laughing, unable to help himself. It was kind of easy to forget Flowey was there from time to time since he was… well, a flower. Frisk looked at Sans and couldn’t help but join in the laughter, hugging the skeleton close. They kissed passionately before agreeing to clean up, both the couch and themselves. It wasn’t until after their shower they realized that they had forgotten protection this time. Sans was embarrassed and immediately apologized.

He was just lucky Frisk was a forgiving woman. That, and she didn’t end up pregnant from their little session.


End file.
